Residual stress-driven delamination in deposited multi-layers

An analysis is presented of the problem of residual stress-driven delamination in materials or parts manufactured by successive layer deposition. A direct application of this work is to parts that are built using rapid prototyping-based layered manufacturing methods. A two-dimensional model is presented that allows calculation of steady-state energy release rates for delamination cracks. Results from a finite element model of the problem are also presented. The results verify the steady-state analysis and show that it is applicable over a wide range of part dimensions. Crack displacement modes are also extracted from the finite element model. Results are presented for two- and four-layer bi-material configurations, over a large range of material mismatches. Examples are given of how this work can be used to identify critical interfaces where delamination is most likely to occur and thus to predict the susceptibility of multi-layers to delamination.